Discrete polymer in fan-out packages

1. A package comprising:

a first first-level device die and a second first-level device die;

a first encapsulant encapsulating the first first-level device die and the second first-level device die therein;

a first build-up structure over and electrically connecting to the first first-level device die, wherein the first build-up structure comprises a first conductive pad;

a second build-up structure over and electrically connecting to the second first-level device die, wherein the second build-up structure comprises a second conductive pad;

a first conductive post over and contacting the first conductive pad;

a second conductive post over and contacting the second conductive pad;

a second-level device die over and attached to the first build-up structure and the second build-up structure; and

a redistribution structure over and electrically connected to the first conductive post, the second conductive post, and the second-level device die.

2. The package of claim 1 , wherein the first build-up structure comprises a first dielectric layer, with the first conductive pad being in the first dielectric layer, and the second build-up structure comprises a second dielectric layer, with the second conductive pad being in the second dielectric layer, and wherein the first dielectric layer and the second dielectric layer are separated from each other by an additional dielectric material.

3. The package of claim 1 , wherein the first first-level device die comprises:

a first portion overlapped by the second-level device die; and

a second portion extending beyond a corresponding edge of the second-level device die.

4. The package of claim 1 , wherein the first encapsulant comprises an intermediate portion between and contacting the first first-level device die and the second first-level device die, and wherein the second-level device die overlaps the intermediate portion.

5. The package of claim 1 , wherein the second-level device die has a front side facing the redistribution structure.

6. The package of claim 1 , wherein the first first-level device die and the second first-level device die comprise front sides facing the second-level device die.

7. The package of claim 1 , wherein a first top surface of the second-level device die is coplanar with second top surfaces of the first conductive post and the second conductive post.

8. The package of claim 1 , wherein the first conductive post and the second conductive post are copper posts.

9. A package comprising:

a first device die and a second device die;

a first conductive post over and connected to the first device die;

a second conductive post over and connected to the second device die;

a third device die overlapping a first portion of the first device die and a first portion of the second device die, wherein the third device die is between the first conductive post and the second conductive post;

a first molding compound molding the third device die, the first conductive post, and the second conductive post therein; and

an interconnect structure over and contacting the third device die, the first conductive post, and the second conductive post.

10. The package of claim 9 , wherein each of the first device die and the second device die further comprises a second portion extending laterally beyond corresponding edges of the third device die.

11. The package of claim 9 further comprising a second molding compound molding both of the first device die and the second device die therein.

12. The package of claim 11 , wherein the second molding compound is in physical contact with the first molding compound.

13. The package of claim 11 , wherein the second molding compound comprises:

a base material; and

partial particles in the base material, wherein the partial particles comprise rounded surfaces contacting the base material, and planar surfaces contacting the first molding compound.

14. The package of claim 9 further comprising:

a first build-up structure over and electrically connecting to the first device die, wherein the first build-up structure comprises a first dielectric layer and a first conductive pad in the first dielectric layer, wherein the first conductive post is in physical contact with the first build-up structure; and

a second build-up structure over and electrically connecting to the second device die, wherein the second build-up structure comprises a second dielectric layer and a second conductive pad in the second dielectric layer, wherein the second conductive post is in physical contact with the second build-up structure.

15. The package of claim 14 , wherein the first conductive post comprises a bottom surface in physical contact with a top surface of the first conductive pad.

16. The package of claim 9 , wherein both of the first conductive post and the second conductive post comprise straight edges penetrating through the first molding compound.

17. A package comprising:

a first device die and a second device die;

a first build-up structure over and electrically connecting to the first device die, wherein the first build-up structure comprises a first dielectric layer and a first conductive pad in the first dielectric layer;

a second build-up structure over and electrically connecting to the second device die, wherein the second build-up structure comprises a second dielectric layer and a second conductive pad in the second dielectric layer;

a molding compound, wherein edges of the first build-up structure and the second build-up structure are in contact with additional edges of the molding compound to form vertical interfaces;

a third device die over and attached to the first build-up structure and the second build-up structure;

through-vias on opposing sides of the third device die; and

a redistribution structure over and electrically connecting to the through-vias and the third device die.

18. The package of claim 17 , wherein the through-vias comprise copper.

19. The package of claim 17 , wherein the first dielectric layer and the second dielectric layer comprise polymers.

20. The package of claim 17 , wherein a combined region comprising the first device die and the second device die extends laterally beyond the third device die in opposite directions.